The first component of the middle ear to receive sound waves is the tympanic membrane, also known as the eardrum. Sound waves striking the tympanic membrane are transmitted through a series of bones (e.g., malleus, incus and stapes) to the cochlea, where the sound waves are sensed and processed.
Tympanic membrane deformities, such as perforations, interfere with the transmission and perception of sound. Perforations are usually caused by trauma or infection. Middle ear infections can cause spontaneous rupture (tear) of the eardrum, resulting in a perforation. A hole in the tympanic membrane may also be caused by surgical procedures, e.g., a small hole may remain in the eardrum after a previously placed pressure equalization tube either falls out or is removed by the physician.
Repair of tympanic membrane perforations is accomplished in a procedure known as tympanoplasty or myringoplasty. Generally, in tympanoplasty or myringoplasty, the hole in the tympanic membrane is repaired by means of a graft. Typical graft materials include natural materials such as temporalis fascia, tragal perichondrium, skin, periosteum, loose overlay tissue, fat, vein tissue, human amniotic membrane, and homologous dura; and non-natural materials such as silastic, paper and teflon sheets. Such typical graft materials used in these procedures, however, may cause further ear infection, loss of hearing, tinnitus, facial paralysis, or hematoma.
Thus, there exists a need for safe and effect materials and techniques to repair defects of the tympanic membrane.